FLOOD06826

• County: Statewide
• Basin: Statewide
• Title: National Economic Development Procedures Manual-Urban Flood Damage
• Date: 3/1/1988
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

Procedure, For each reach, an "index point" can be selected which

will indicate the average relation between stage and discharge, In a

rural reach, the "index point" may be the nearest established stream

gaging station, at the nearest community, or a point near the center of

the reach. In damage centers or developed areas, it may be necessary to

make computations for a series of discharges in order to develop "rating

curves" at several index points so that the sub-reach may be adequately

evaluated,

Advancements in computer software and aerial photography have

facilitated the use of 'flood profile methods for referencing the location

of floodplain property and calculating damages, The profile method

reference each structure to a specific location, usually within one-tenth

of a mile of the distance from the mouth of the stream or river, Flood

profiles that give elevations for the range of lo~tions within the reach

are then used to relate the frequency and elevation of flooding at each

location, The profile method is more accurate than using index points

because it takes into account any variations in the slope of the flood

profiles within each reach, and instead of the average locations of the

buildings within each reach, damages are calculated for specific location

of each structure,

In addition to the technical considerations above, reaches and index

points should be selected so as to permit separation and identification of
damages and benefits in each political entity village, city, county or
parish, and state. Ordinarily, this will not be found to increase the
subdivision of reaches unduly, and the final summary may again combine

v-a